Grease gun



Feb. 1o, 194s. 2,435,647

M. O. ENGSETH GREASE GUN Filed Feb. 2l, 1945 2 Sheets-Sheet 1 u SII 44N u v15' wrs www Feb, 10, 1948. M. o. ENGsl-:TH

GREASE GUN Filed Feb. 21, l1945 2 Sheets-Sheet 2 gm Re E Se m: e: f/e

Marhn O. Ersefh 9543 @www Patented Feb. 10, 1948 UNITED STATES PATENT: .OFFICE ...'mf Martin 0. Engseth, Minneapolis, Minn. Appufi'onlelllll'sy. 21(,C,N0. 579,039

My invention relates to grease guns and has for an object to provide a grease gun by means of which high pressure can be procured through 1' manual manipulation. Anotherobject of the invention'resides in providing a grease gun operating on the principle of impact. i

A still further object of the invention resides -in providing a grease gun having a cylinder and der to create a pressure in the cylinder.

Another object of the invention resides in providing a retracting mechanism for retracting the piston and compressing the resilient means and in still further providing release means for releasing the piston after the resilient means has been suiliciently compressed.

An object of the invention resides in providing a lever for retracting the pistonand in providing the lever with a catch for engagement with a part movable with the piston and in constructing the release means to disengage the catch when the piston is fully retracted and the resilient means compressed.

Another object of the invention resides in providing cushioning means for retarding the movement .of the piston near the end of its pressure stroke.

Other objects of the invention reside in the novel combinationV and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings:

Fig. 1 is an elevational longitudinal sectional view of a grease gun illustrating an embodiment of my invention and showing the piston in extended position.

Fig. 2 is a view similar to Fig. -1 of a portion of the structure shown therein and illustrating the arrangement of the parts when the piston is in retracted position.

Fig. 3 is a cross sectional view taken on line 3 3 of Fig. l. f

Fig. 4 is a view similar to Fig. 1 of a modication of the invention.

Fig. 5 is a view similar to Fig. 2 of the struc-- cessive movement of the operating parts required 2 Such equipment requires electrically operated pumps and other elaborate equipment. Other devices in which high pressure has Abeen attempted to be procured by manual manipulation have been exceedingly cumbersome, due to exto produce the pressure or due to the use of screws or similar devices. The present invention provides a simple construction whereby the high pressures necessary are easily procured in a natural and simple manner by simply manipulating an easily operated lever and without the use of extensive and elaborate equipment.

'I'he form of my invention shown in Figs. 1, 2 and 3 comprises a body I0 in which the operating parts ofthe device are disposed and to which is attached a receptacle II for the lubricant. In the body I0 is formed a cylinder I2 in which a piston I3 is slidable. vThis piston is adapted to be retracted by a retractingmechanism I4 carried by the body I0 which compresses a compression coil spring I5. Upon release of the spring I5 bymeans of a release mechanism I6, the said spring forces the piston I3 to travel along the cylinder I2 and to compress the lubricant within said cylinder and discharge the same into the lubricating fitting or other device into which the lubricant is to be forced. The various parts forming the instant invention will now be described in detail.

The body I0 of the grease gun consists of a casting generally tubular inform which-has a bore therein forming the cylinder I2 previously referred to and which extends throughout a portion of the length thereof. The cylinder I2 is of rather small dimensions, so that when the piston I3 is forced along the same, suitable pressure can be procured within said cylinder. The body I0 has a rearward portion I1 which is formed with a bore I8 concentric with and lying in continuation of the bore forming cylinder I2. The bore' I8 is of considerably greater diameter than the cylinder I2 and receives the compression spring I5. Slidably mounted in the bore I8 is a plunger I9 which is attached to the piston I3. The spring I5 bears at one end against the plunger I9- and at its other end against a plug 2l screwed into the end of the portion I1 of body Ill. The body I0 has attached to it a handle 22 which may be cast integral therewith or attached to the body in any suitable manner.

The receptacle Il consists of a tube 23 having a cylindrical chamber 24 extending throughout the length thereof. One end of the tube 23 is screwed into a threaded boss 25 cast as a part of the body I0. This boss has a passageway 23 therein which communicates with thelcylinder I2 intermediate the length thereof and with the cylindrical chamber 24 in tube 23. A cap 21,

screwed upon the other end of the tube 23, closes 5 such end of the same. Slidably mounted within the cylindrical chamber 24 is a piston 28 of any suitable construction which is attached to a pis` ton krod 29. The said rod extends though the cap 21 and has attachedto its outer end a knob lo 32 by means of which the piston may be manually manipulated. A compression coil 3| disposed within the cylindrical chamber 24 bears against the piston 28 and'against the cap 21 and tends to urge the piston for movement toward l5 The receptacle II may be filled with luloricant '20 by removing the tube 23 from the boss 25 and inserting the open end of the tube 23-into the lubricant. Upon then drawing the piston 28VY` inwardly into the cylinder and against the action of the spring 3|, the chamber 24 ahead of the 25 piston may be filled with lubricant. Totemporarily hold the charge oi lubricant within-the cylinder, a shoulder 34 is formed on the piston g rod 29 which is adapted to engage a shoulder 35 on the cap 21 when the piston rod is moved V30 l laterally. The tube 23 with its charge of lubricant is then screwed back into the boss iii-.andV upon disengagement, the grease gun is ready to be used.

Where lubricant under pressure is available. 35

the receptacle Il may be filled without removing the tube 23 from the boss 2li.- For this purpose, a fitting 36 is employed which may be connected to a source of lubricant.' This fitting is screwed inder i2 and the boss 25. and has a passageway 31 through the same which communicates with a passageway 38 in the said body which, in turn, communicates with the passageway 23 previously mentioned. A check valve 33 within the fitting 33 45.1,

permits the flow of lubricant into the receptacle, but restrains the flow of lubricant out of the, same. When the receptacle Il is to be lled, the

fitting 36 is connected to the source of lubricantY and the lubricant flows past the check valve 39 50' and into the portion of the chamber24 ahead oi piston 28. This causes the piston to move toward the cap 21 and to compress the spring 3l.

The cylinder I2 of body l0 has screwed into the end of the same a fitting 4I by means of which 55 the lubricant maybe directed to the desired locality. This fitting may be oi' any of the standard fittings now used for lubrication purposes o r the same may be merely a tube or pipe leading the lubricant to the desired locality. Between 80 lthe fitting 4I and the bore I2 is provided a check valve 42 which permits the flow ofi'lubri'cant fromthe cylinder I2 and into the fitting 4I, but which restricts flow of lubricant or air in the oppositev direction. 65

The retracting mechanism I4 consists of a lever 43 preferably constructed of sheet metal which has two spaced arms 44 straddling the ext tension I1 of body Ill and best shown in Figs. l

1 and 2. These arms are connected together by 70 means of a connecting portion 45 disposed at the forward portion of said handle. The two arms are pivoted to a lug 48 formed on the extension I1 by means of a pintle 41 which extends throughthe said arms and through the lug 4 6. Lever [43," 'IISl when" in its extended position. is disposed as shown in Fig. 1 and may be forced rearwardly toward thei handle 22 to a position slightly past l that illustrated in F18. 3.'

The release mechanism II consists of ai catch 3| which extends through the space'between .the two arms 44 of lever 43 and is pivotally mounted on a pintle l2 extending throughsaid arms. This catch hasn ringer I3 at the end o! the same which is'adapted to engage a radially extending shoulder 54 on the plunger I3 which shoulder is formed by constructing the said plunger with a V-shaped groove I3 extending about the same.

. The groove il also forms an annular abutment 43 on said plunger which serves a purpose to be presentlygdescribed in detail. The finger 53 has a fulcr 33 which, when the parts are, arranged -as shown" in Fig. 1, engages the abutment 49.

The catch II operates'in a groove 53 formed in the under side of the extension I1 oi body I0 and communicatesfwith the bore I8. The finger 33 is urged into engagement'with the shoulder .l

54 by means of a. spring 51. This spring, inter- V mediate the-ends thereof, is loopedI about the pintle 52, as indicated at 33. The end 59 of this spring is hooked under the'catchv 5I, while the other end 3l ot said spring extends through hole 32 in the handle 22 and is anchored to said han- .dle. The spring l1 also serves to urge lever 43 'for movement from the position shown in Fig. 3

to-that shown in nig. 1.. when the lever u 1s moved toward the handle 22, finger 53 engages the shoulder 54 and drawsthe plunger `I3 rearwardly against the action ot the spring I3. 'I'he location of the pintle I2 is such that when the leverA43 moves toward the handle 22 the said pintle moves downwardly. This swings the/catch 5I which causes the i'ulcrum 63 of thecatchjl to be urged against the abutment 49 and the finger into the body I0 at a locality between the cyl- 40 53 to be gradually withdrawn from engagement therewith. Such movement continues until the parts reach a position such as shown in Fig. 2. During such movement of the plunger I9 and piston I3, said piston is retracted from the cylinder I2 and a vacuum created therein. As soon as the piston I3 passes the passageway 23, the vacuum created in the bore otcylinder I2, aidedby the pressure produced by the spring 3. causesl the lubricant in the 'portion of the chamber 24 ahead of the piston to fill the cylinder I2 ahead o1' the piston I3. Further movement of the lever 43 causes the finger 53 to become disengaged from the shoulder I4 and to free the plunger` I3, Spring .I5 then forces the plunger I3 forwardly. causing piston I3 to travel along the cylinder I2 and to compress the lubricant therein and. dis-v charge the same past the valve 42, and into the fitting 4I.

The groove 53, in the portion Il of body Il. falls short of the end of the bore I3 adjacent the cylinder I2. This provides a pocket 34 into which the end of the plunger I3 is directed. The plunger I3 fits suiliciently closely within the bore I3 so that the seid pocket forms a eyunder andthe I vious. Each In Figs. 4 and 5, I have shown a modiilc'ation of the invention. In this form of the invention, a body I I is employed which has Ia laterally projecting portion formed at its extreme end with a handle ||2. Theportion has a bore forming a cylinder |13 of small diameter which engages an abutment |33 also formed on the plunger |I5. The lever III an the catch |35 are urged into the position shown n Fig. 4 bymeans of a spring |4| having a portion |42 looped about the pintle |50. I'he .said spring has an end |43 engaging the catch |35 and another end |44 engaging the portion |34 of lever |3I. Spring |4| operates to urge the catch into engagement with th plunger III and also urges the lever I3| away v from the handle ||2.

The slot |40 in handle ||2 terminates short oi' the end of the bore IIB to form a pocket |45 similar to the pocket 54 of the other formof the invention. which provides a cushion for cushioning corresponds to the cylinder I2 of the other form of the invention. In this cylinder is slidably lmounteda piston ||4 which has attached to it a plunger |I5. Plunger I|5 slides ina bore IIs in the handle ||2 and is urged toward the cylinder I|3 by means of a compression coil spring ||1 This spring is seated at one end against the plunger |I5 and at its,other end against a plug II8 screwed into the end of handle ||2. The cylinder I3 communicates with a passageway I I 9 formed in the body |I0. The body ||0 has secured to it a tting |2| which communicates through a check valve |22 with the passage- Rearwardly `of the transverse portion of body I0 is provided a boss |23 which is threaded to receivea receptacle|24 for the lubricant. This receptacle has a cap |25 secured to the end of the same. In the form of the receptacle shown in Figs. 4 and 5, a cartridge |25 is employed which contains the desired lubricant. This cartridge is inserted into the receptacle |24 and is removed therefrom when empty. For` ejecting the lubricant from the receptacle |24, a compression coil spring |21 is employed which is attached at one end to the cap |25 and at its otherend to a piston |28 slidable along the interior of the cartridge |26. The interior of the receptacle |24 communicates through a passageway |30 with the cylinder ||3 -1 The receptacle |24 may be illed with lubricant in the same manner as the other form of the invention. For this purpose, a fitting |29 is employed identical with the iitting 3B which is screwed into the boss |23 and communicates with the interior of the receptacle |24. Due to the' similarity of these devices, the fitting |29 has not been shown in detail in the drawings. 4If desired, however, a receptacle similar to that shown in Fig. 1 may be used instead of the one shown.

For operating the grease gun shown in Figs. 4 and 5, alever |3| is employed which-is similar in construction to the lever 43. This lever has spaced arms |32 which straddle the body IIII and are pivoted to it by means of a pintle |33 extending jointly through said arms and body. The arms |32 are connected together by means of a connecting portion |34 simil-ar to the portion 45 of handle 43. The lever |3| has pivoted to it a catch |35 which is mounted on a pintle |50 extending through the arms |32 at a locality below the body ||Il This arm terminates in a linger. |36 which extends through a slot |40 in the han-. die |I2`and operates in the samey manner as the hook 53 on catch 5|'. This vfinger engages a the action 'of the plunger I5.

The operation of the form of the invention shown in Figs. 4 and 5 is similar to the operation of the device shown in Figs. 1 and 2. The fulcrum I 38 rocks on the abutment |33 and withdraws the finger |33 from engagement with the shoulder |31 as the lever is drawn toward the handle ||2. In the same manner, grease is drawn into\the bore ||3 and discharged through theI fitting 2| when the plunger is released.

The advantages of my invention are manifest. An extremely simple and practical construction is provided serviceablefor all general greasing problems. VThe device does not require extensive equipment for operation or for filling. Extremely high pressures can be procured by simple manipulation; The device can be constructed at a reasonable expense. My invention will function for an appreciable period of time without repair.

Changes in the specific form of my invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of my invention.

Having described my invention, what I vclaim 7 as new and desire to protect by Letters Patent is:

' 1.1In agrease gun, a body providing a cylinder, a'piston slidable along said cylinder, aguide said cylinder and to be retracted upon movement of the plunger in the opposite direction, a

shoulder formed on said plunger, a lever pivoted relative to said body, -retracting means on said leverA forengaging said shoulder to cause the 1plunger to retract the resilient means upon movement.y of the lever in one direction and means for disengaging said plunger from said retracting meansl upon retraction of said resilient means.

2. In a grease gun, a body having a bore therein providing a cylinder, means for directing lubricant into said bore, a second bore in said body concentric with said first bore and of larger dimensions, a piston slidable alng said cylinder, a plunger attached to `said piston andslidable along said second bore, a plug in the end of said second bore, a compression coil spring acting between said plug and plunger for urging sai`d` piston for movement along said cylinder, said body having a slot therein communicating. with ,plunger from engagement with said retracting shoulder I 31 formed on the plunger ||5. The

3. lIn a grease gun, a body having a bore therein providing a cylinder, means for directing vlubricant .into said bore. a second bore in said body a plunger attached to along said second bore. a plug in the end of said second bore, a compression coil spring acts l ing between said plug and plunger ior urging said piston for .movement along said cylinder,

' said body having a slot therein communicating with said second bore. a. lever pivoted to said body,

a catch pivoted to said ever and operable through l0 -said slot. a shoulder formed on said plunger and engageable by said catchand releasing means for disengaging said catch ironvsaid shoulder upon I lretraction 'of said spring. e i

4. In a grease gun. abody having a bore theregg in providing a cylinder, means for directing lubricant into said bore, a. second bore in said body concentric with said ilrst-bore and of larger dii mensions, a piston slidable along said cylinder, a A I plunger 'attached to said piston and slidable along m ber adapted to engage said shoulder, guide means said plug and plunger for urging said piston for movement along said cylinder, said body having a slot therein communicating with said second bore.

said second bore, a plug in theend oi said second bore, a compression coill spring acting between a lever'pivoted tosaid body, a catch` pivoted to said lever and operable through said slot, a shoulder -formed on said plunger. a ilnger formed on said catch and engageable with said shoulder,

a iulcrum formed on said catch and an abutment '30 on said plunger engageable with said fulcrum and serving'to swing said linger out of engagement with said shoulder upon manipulation of said lever to release said plunger andl piston.l

5. -In a grease gunna body having a bore thereas in providing a cylinder, means fordirecting lubricant into said bore. a second bore in said body concentric with said rstA bore and of larger dimensions, a. piston slidable along said cylinder, a

plunger attached to said piston and slidable along 4o said second bore, a plug in the .end o i' `said sec- .ond bore, a compression coil pring acting between said plug and plunger fo urging said pis'- tonv for. movement along said cylinder, said bodyL having a slot therein communicating with said 45 `second bore. a lever pivoted relative to said body,

- a catch pivoted to said lever and operable through said slot. the pivot for said catch being disposed in proximity to said body' at the locality of said slot, the pivot :lor said lever`being so disposed 50 that thepivot for said catch moves in a directionl away rfrom said body upon retraction oi' said 1ever.. a shoulder on said plungenan abutment ad-I joining said shoulder, a linger on said catch for engagement with said shoulder anda fulcrum 55 on said catch for engagement with said abutment, said fuicrum moving the ilnger out` of engagement with said shoulder lupon retraction of said lever and the swinging ofthe pivot for said catch away from the body.

6. In a -grease gun, a

body monding e eynnl der. a piston slidable along said cylinder, a guide carried by said body. a plunger for operating' saidv piston, and movable along said guide, resilient means acting on said plunger and being adapted to urge the. plunger for movement along .said guide and Asaid piston for movement along said cylinder and to'be retracted upon movement or the plunger in the opposite direction, a shoulder iormed on said plunger. a' movable member adapted to engage said shoulder and upon movement to Aretract said resilient means. manually operated neans iormoving saidmovable mem- 'ille oi this patent:

from said shoulder after retraction of the resilient means;l

'1. Ina grease gun, a body providing a cylinder. apiston slidable along said cylinder, reciprocable means movable with said fpiston. a shoulder formed on said reciprocable means, retractable resilient means adapted'to urge the piston for movement along said cylinder, a movable "f'member adapted to engage said shoulder and upon movement to retract said resilient means, manually Ioperated means for moving said member.

and means for disengaging said member from said movement along said cylinder, a movable memi'or guiding said movable member for reciprocating movement inthe direction of movement ofy said reciprocable means and for swinging movement relative` the locality-of engagement oi' said movable member with said shoulder, and release means operable upon swinging oi' said member for vdisengagingsaid member from said shoulderto` release the piston. Y

9. In a grease gun, a body providing a cylinder, a piston slidable along said cylinder, reciprocable meansmovable with said piston, a shoulder formed on said reciprocable means. retractable resilient means adapted to urge the piston for' movement along said cylinder, ya movable member adapted toengage said'shoulder, guide means for guiding said movable member for'reciprocating movement in. the direction of movement of said reciprocable means andV for'swinging move- 'ment relative the locality of engagement of said movable member with saidvshoulder, an abutment formed on said reciprocable means adiacent said shoulder and means on said movable element engaging said abutment and serving upon swinging of said movable member to disengage said movable member from said shoulder to release the piston. 10. In a grease gun, a body providing a cylinder, a piston slidable along'said cylinder, re-

ciprocable means movable with said piston, said reciprocable means having a groove therein forming a shoulder and an angularly disposed abutment, retractable resilient means adapted to urge the piston for movement along said cylinder, a movable member, a catch thereon adapted to engage saidshoulder, guide means for guiding said movable member for reciprocating movement in thedirection of movement of said reciprocable means and for swinging movement relative to the locality of engagement of said catch with said shoulder and a fulcrum formed on said movable member and adapted toengage said abutment to move said catch out or engagement with the shoulderl upon swinging of said movable member.

MARTINO. ENGSETH.

nitraat-:NCES CITED The following references are of record in the g UNITED STATES PATENTS Number Name Date 1,259,463 Der'ir Mar. 12, 191s- 1,976,903 Teal' ...Oct 16, 1934' I per. and means for disenga'ging said member iu'y 2,151,676 Appleby Mar. 28, 1939 

